Mercurial > rinkhals
view gamelib/animal.py @ 77:65958516c7d9
Implement separate fence repair cost (currently 25 groats).
author | Simon Cross <hodgestar@gmail.com> |
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date | Tue, 01 Sep 2009 10:40:57 +0000 |
parents | aa4bd93575d9 |
children | bf28f499c6b4 |
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"""Class for the various animals in the game""" from pgu.vid import Sprite from pgu.algo import getline import imagecache import tiles from misc import Position class Animal(Sprite): """Base class for animals""" def __init__(self, image_left, image_right, tile_pos): # Create the animal somewhere far off screen Sprite.__init__(self, image_left, (-1000, -1000)) self.image_left = image_left self.image_right = image_right self.pos = Position(tile_pos[0], tile_pos[1]) def loop(self, tv, _sprite): ppos = tv.tile_to_view(self.pos.to_tuple()) self.rect.x = ppos[0] self.rect.y = ppos[1] def move(self, state): """Given the game state, return a new position for the object""" # Default is not to move pass def _fix_face(self, final_pos): """Set the face correctly""" if final_pos.left_of(self.pos): self.setimage(self.image_left) elif final_pos.right_of(self.pos): self.setimage(self.image_right) class Chicken(Animal): """A chicken""" def __init__(self, pos): image_left = imagecache.load_image('sprites/chkn.png') image_right = imagecache.load_image('sprites/chkn.png', ("right_facing",)) Animal.__init__(self, image_left, image_right, pos) def move(self, gameboard): """A free chicken will move away from other free chickens""" pass class Egg(Animal): """An egg""" def __init__(self, pos): image = imagecache.load_image('sprites/egg.png') Animal.__init__(self, image, image, pos) # Eggs don't move class Fox(Animal): """A fox""" costs = { # weighting for movement calculation 'grassland' : 2, 'woodland' : 1, # Try to keep to the woods if possible 'broken fence' : 2, 'fence' : 10, 'guardtower' : 2, # We can pass under towers 'henhouse' : 2, } def __init__(self, pos): image_left = imagecache.load_image('sprites/fox.png') image_right = imagecache.load_image('sprites/fox.png', ("right_facing",)) Animal.__init__(self, image_left, image_right, pos) self.landmarks = [self.pos] self.hunting = True self.dig_pos = None self.tick = 0 def _cost_path(self, path, gameboard): """Calculate the cost of a path""" total = 0 for pos in path: if gameboard.in_bounds(pos): this_tile = gameboard.tv.get(pos.to_tuple()) cost = self.costs.get(tiles.TILE_MAP[this_tile], 100) else: cost = 100 # Out of bounds is expensive total += cost return total def _gen_path(self, start_pos, final_pos): """Construct a direct path from start_pos to final_pos, excluding start_pos""" if abs(start_pos.x - final_pos.x) < 2 and \ abs(start_pos.y - final_pos.y) < 2: # pgu gets this case wrong on occasion. return [final_pos] start = start_pos.to_tuple() end = final_pos.to_tuple() points = getline(start, end) points.remove(start) # exclude start_pos if end not in points: # Rounding errors in getline cause this points.append(end) return [Position(x[0], x[1]) for x in points] def _find_best_path_step(self, final_pos, gameboard): """Find the cheapest path to final_pos, and return the next step along the path.""" # We calculate the cost of the direct path direct_path = self._gen_path(self.pos, final_pos) min_cost = self._cost_path(direct_path, gameboard) min_path = direct_path # is there a point nearby that gives us a cheaper direct path? # This is delibrately not finding the optimal path, as I don't # want the foxes to be too intelligent, although the implementation # isn't well optimised yet poss = [Position(x, y) for x in range(self.pos.x - 2, self.pos.x + 3) for y in range(self.pos.y - 2, self.pos.y + 3)] for start in poss: if start == self.pos: continue # don't repeat work we don't need to cand_path = self._gen_path(self.pos, start) + \ self._gen_path(start, final_pos) cost = self._cost_path(cand_path, gameboard) if cost < min_cost: min_cost = cost min_path = cand_path if not min_path: return final_pos return min_path[0] def _find_path_to_woodland(self, gameboard): """Dive back to woodland through the landmarks""" # find the closest point to our current location in walked path if self.pos == self.landmarks[-1]: if len(self.landmarks) > 1: self.landmarks.pop() # Moving to the next landmark else: # Safely back at the start return self.pos return self._find_best_path_step(self.landmarks[-1], gameboard) def _find_path_to_chicken(self, gameboard): """Find the path to the closest chicken""" # Find the closest chicken min_dist = 999 closest = None for chicken in gameboard.chickens: dist = chicken.pos.dist(self.pos) if dist < min_dist: min_dist = dist closest = chicken if not closest: # No more chickens, so leave self.hunting = False return self.pos if closest.pos == self.pos: # Caught a chicken gameboard.remove_chicken(closest) self.hunting = False return self.pos return self._find_best_path_step(closest.pos, gameboard) def _update_pos(self, gameboard, new_pos): """Update the position, making sure we don't step on other foxes""" final_pos = new_pos moves = [Position(x, y) for x in range(self.pos.x-1, self.pos.x + 2) for y in range(self.pos.y-1, self.pos.y + 2)] blocked = False for fox in gameboard.foxes: if fox is not self and fox.pos == new_pos: blocked = True if fox.pos in moves: moves.remove(fox.pos) if blocked: # find the closest point in moves to new_pos that's not a fence final_pos = None dist = 10 for poss in moves: if gameboard.in_bounds(poss): this_tile = gameboard.tv.get(poss.to_tuple()) else: this_tile = tiles.REVERSE_TILE_MAP['woodland'] new_dist = poss.dist(new_pos) if new_dist < dist: dist = new_dist final_pos = poss if gameboard.in_bounds(final_pos): this_tile = gameboard.tv.get(final_pos.to_tuple()) else: this_tile = tiles.REVERSE_TILE_MAP['woodland'] if tiles.TILE_MAP[this_tile] == 'broken fence' and self.hunting: # We'll head back towards the holes we make/find self.landmarks.append(final_pos) elif tiles.TILE_MAP[this_tile] == 'fence' and not self.dig_pos: self.tick = 5 self.dig_pos = final_pos return self.pos return final_pos def move(self, gameboard): """Foxes will aim to move towards the closest henhouse or free chicken""" if self.dig_pos: if self.tick: # We're digging through the fence self.tick -= 1 # Check the another fox hasn't dug a hole for us # We're top busy digging to notice if a hole appears nearby, # but we'll notice if the fence we're digging vanishes this_tile = gameboard.tv.get(self.dig_pos.to_tuple()) if tiles.TILE_MAP[this_tile] == 'broken fence': self.tick = 0 else: # We've dug through the fence, so make a hole gameboard.tv.set(self.dig_pos.to_tuple(), tiles.REVERSE_TILE_MAP['broken fence']) self.dig_pos = None return if self.hunting: desired_pos = self._find_path_to_chicken(gameboard) else: desired_pos = self._find_path_to_woodland(gameboard) final_pos = self._update_pos(gameboard, desired_pos) self._fix_face(final_pos) self.pos = final_pos